The invention is in an attachment, for small loaders, that can grip a long pole, lift the pole, move the pole between a horizontal position and a vertical position and move the pole vertically while it is in a vertical position.
Buildings commonly referred to as pole barns are used on farms and in other locations for storage buildings as well as for enclosed workspace. These buildings are constructed using long poles with a lower end embedded in the ground. The poles generally have a square or rectangular cross section. Normal cross section sizes are 4 inches by 4 inches, 4 inches by 6 inches, or 6 inches by 6 inches. The length of the poles vary from about 14 feet to well over 20 feet. The poles are inserted into holes bored in the ground. Normally the holes are sufficiently deep to place the bottom of each pole on soil that does not freeze in the winter. Generally the holes for the poles are 4 to 6 feet deep. Buildings that are used for storing farm machinery such as grain harvesters, require 12 feet or so of vertical space plus space for an overhead door. For many such buildings the poles are 18 to 24 feet long. The walls are constructed by attaching horizontal beams to the poles. Sheet metal panels are attached to the beams to form side walls. Roof trusses are supported by the poles. Purlins and sheet metal panels are attached to the trusses to completely enclose the interior space.
The poles that are used for pole barns are treated with wood preservatives to reduce rot and insect damage. The preservatives penetrate into the wood and may increase the weight of the poles somewhat. A 4 inch by 4 inch pole 24 feet long can easily be lifted and moved manually by two people. Such a pole can most likely be lifted by one person but is somewhat difficult to move around due to its length. It is also difficult to manually move such a pole to a vertical position due to the extended distance between the center of gravity of the pole and the upper end of the pole from the lower end of the pole where it can be held by an individual. Once a 24 foot wood pole is in a vertical position it can be difficult to manually hold the pole in a vertical position. Lowering a pole 8 feet long into a small diameter hole 4 feet or so deep is difficult if the pole cannot be easily held in one hand.
Machines are available for handling logs and utility poles. These machines are usually large and expensive units that are capable of moving large diameter logs and utility poles. Some of the machines can move multiple poles simultaneously.
Logs are severed from their roots where they grew and placed horizontally on the ground. Once logs are in a horizontal position, they often remain generally horizontal for storage, transport and for sawing into lumber. Machines for handling logs generally do not require the capability of moving a log from a horizontal position to a vertical position.
Logs are initially covered by bark. The bark provides protection for the underlying wood. Grapples can, as a result of the protection provided by the bark, apply substantial gripping force on a log. Utility poles have rough outer surfaces and do not require flat surfaces for the attachment of wall supports or other structure. As a result utility poles can generally be handled by grapples with a minimum number of grasping arms that squeeze their outer surface. Lumber on the other hand must be handled with some care to prevent damage to flat surfaces.
The pole handler attachment has a base frame that is adapted to be pivotally attached to a boom of an earth moving tractor for pivotal movement about a transverse horizontal axis. A trunnion is fixed to the base frame, extends forward from the base frame and has a trunnion axis that is perpendicular to the transverse horizontal axis. The trunnion axis is horizontal when the base frame is in a vertical position. A sleeve is telescopically received on the trunnion and axially retained on the trunnion. A fixed clamp assembly is secured to the sleeve and has a first pole clamp member and a second pole clamp member that cooperate to position one pole in a position that is generally transverse to the trunnion axis. A movable clamp assembly is pivotally attached to the sleeve for pivotal movement about a hinge axis that is perpendicular to the trunnion axis. A hydraulic clamping cylinder is pivotally attached to the sleeve and to the movable clamp assembly. The clamping cylinder is operable to pivot the movable clamp assembly about the hinge axis, and move the third pole clamp member toward the first pole clamp member and the second pole clamp member. A tilt hydraulic cylinder pivotally connected to the base frame and to the sleeve is operable to pivot the sleeve about the trunnion axis to move one pole held by the fixed clamp assembly and the movable clamp assembly between a horizontal position and a vertical position when the trunnion axis is horizontal.